Battery Train

This is a battery from my earphones. The batteries are set in a way in which they are faced opposite ways next to each other. The reason for this is because batteries produce the charge that keeps the earphones running at the speed at which they run. Both is these batteries are a 1.5 volt battery and there are two of them so together they create a 3 volt charge to the earphones. The reason why they are faced opposite ways like this is because the charges are like water; they flow. Charge, like water flows from an area of high potential to an area of low potential. The batteries need to flow, so that is why the batteries are in this formation. This formation in which the batteries are formed in is called a series.